Electric space heater



April 21, 1959 R. ol` WINTHER ELECTRIC SPACE HEATER Filed March 5 1957 3 Sheets-Sheet 1 April 21, 1959 R. o. WINTHER 2,883,512

ELECTRIC SPACE HEATER f5 il April 21, 1959 R. o. lwlN'rl-IER 2,883,512

ELECTRIC SPACE HEATER Filed March 5, 1957 3 Sheets-Sheet S5 v I y INVENIOR. E E1. deff @,Wzgzief,

BY M4, ff/cq United States Patent Office ELECTRIC SPACE HEATER Robert 0. Winther, Menominee,

Seeley Corporation, of Michigan Mich., assignor to King- Ann Arbor, Mich., a corporation This invention relates to electric space heaters, and, more particularly, to an improved electric space heater of the combined radiant and forced air circulation type.

One object of the present invention is to overcome disadvantages in prior heaters of the indicated character and to provide an improved portable electric space heater of the type commonly used for heating small rooms or for spot heating selected portions of larger rooms.

Another object of the invention is to provide an improved electrical heating device capable of heating a relatively large volume of space with improved uniformity.

Another object of the invention is to provide an improved electrical heating fdevice of the combined radiant and forced air circulation type incorporating improved means for heating air within the device and expelling the air so heated at a relatively high velocity, thereby to extend the heated zone relatively far outwardly in front of the device.

Another object of the invention is to provide an improved heating device incorporating improved means for circulating air around localized heating elements.

Another object of the invention is to provide an irnproved electrical heating device incorporating improved support means.

The'above as well as other objects and advantages of the present invention will 4become apparent from the following description, the appended claims and the aecompanying drawings wherein:

Figure 1 is a front elevational view of a space heater embodying the present invention, certain portions thereof being lbroken away to show the interior structure;

Fig. 2 is a cross-sectional view of the space heater shown in Figure 1, taken along the section line 2-2 thereof;

Fig. 3 is a fragmentary view of a portion of the space heater as shown in Fig. 2, viewed in the direction of the arrow 3 thereof;

Fig. 4 is a `cross-sectional view of the space heater as shown in Figure 1, taken along the section line 4 4 thereof; and

Fig. 5 is a schematic circuit `diagram illustrating the electrical circuit arrangement of the space heater shown in the preceding figures.

Referring to the drawings, a space heater embodying the present invention is shown as comprised of a sheet metal housing which is generally parabolic in transverse cross-section, the operative elements of the heater being carried by the housing. The housing 10 includes curved upper and lower rear wall portions 12 and 13, respectively, end walls 14 and 16, and a [front wall 18. The front wall 18 includes upper and lower portions 20 and 22 and is ycentrally inwardly bent so that the upper and lower portions 20 and 22 are not parallel but are angled slightly towards each other. The rear wall portions 12 and 13, the end walls 14 and 16, and the front wall 18 are all secured together along their edges, as by screws 19, to form a rigid housing. In its upright position as illustrated in the drawings, the housing is supported upon 2,883,512 Patented Apr. 21, 1959 a pair of relatively short front legs 24 that may be welded or otherwise secured to the lower portion 13 of the rear wall, and upon a single rear support member 26, the de tailed structure of which will now be described.

The rear support member 26 may be made of a single strip of metal or any other desired material, and includes an elongated lower leg portion 28 and an upper handle portion 30. The entire lower leg portion 28 is preferably curved to rconform to the curvature of the upper portion 12 of the housing member, although the lowermost part of the leg portion 28 need not be curved but may be made straight, or bent, as desired. The tilt of the heater may be adjusted by varying the position of the rear support member 26 relative to the housing 10. The upper rear wall portion 12 is `centrally apertured to receive a screw 34, the screw 34 extending through a channel 36 which is welded or otherwise rigidly secured to the exterior of the rear wall portion 12 and is shaped to conform thereto, extending generally vertically therealong. The channel 36 is slightly wider than the rear support member 26, and is adapted to receive the rear support member 26 and to hold it firmly in alignment upon the housing. A longitudinal slot 38 is provided in the rear support member near the upper end of the leg portion 28, and the screw 34 is passed through this slot 38. A knob 40 is fixed at the outer end of the screw 34 while the inner portion of the screw extends through the channel 36 and threadably engages a nut 42 xed to the rear wall portion 12. Thus, the rear support member 26 is slidably mounted upon the upper rear wall portion 12 for limited adjusting travel thereon. The knob 40 may be turned to tighten the screw 34 and to draw the knob against the rear support member 26 to yclamp the member 26 firmly in position in the channel 36. Thus, the effective height of the rear leg portion 28 may be adjusted to vary the tilt angle at which the housing 10 is supported.

vAt the same time, the outwardly bent upper handle portion 30 of the rear support member 26 provides a convenient carrying grip for transporting the heater from room to room, or for otherwise moving it about as desired.

A pair of electrical heating elements 46 and 48 are mounted horizontally within the housing structure one above the other, the element 46 'being located behind the upper portion 20 of the lfront wall, while the element 48 is located behind the lower portion 22 of the front housing wall 18.

Separate reilectors 50 and 52 are provided for each of the heating elements 46 and 48, respectively. These reflectors 50 and 52 may ,be generally similar in shape and are preferably made `generally parabolic in cross-section so that they direct radiant Iheat from the heating elements 46 and 48 generally forwardly through longitudinal apertures 54 and 56 dened by the front wall 18, the direction of maximum reected radiation being generally parallel to the transverse horizontal axis of the housing structure as shown. It will be noted that due to the inward slant of the upper and lower front wall portions 20 and 22, the `central longitudinal edges 58 and 60 of the reflectors 50 and 52 do not extend forwardly as far as the outer edges 62 and 64, respectively, of the reflectors. The reliected radiation, therefore, is beamed slightly upwardly from the lower reflector 52 and slightly downwardly from the upper reflector 50 providing an overlapping region `extending generally axially forwardly in which the radiant heat is most highly concentrated. The apertures 54 and 56 in the respective front wall portions 20 and 22 extend along substantially the entire forward sides of the reflectors 50 and 52, and are preferably covered by ornamental wire grills 72 or by any other desired grill work to prevent accidental contact with the heating elements 46 and 48 during operation of the device.

The reflectors 50 and 52 may he made of any desired reflective and heat resistant material, such as polished sheet aluminum or chromium plated steel. They are provided with end walls 66 and 68 between which the electrical heating elements 46 and 48 are mounted in any desired manner. Typically, these elements may be mounted upon tubular ceramic members 70 fitted through apertures in the end walls 66 and 68. These electrical heating elements may be of any desired character, such as resistance Wire coils wound upon ceramic cores. In operation, the heating elements 46 and 48 are heated by the passage of electric current therethrough, and a portion of the heat is radiated directly outwardly through the apertures 54 and 56. Other portions of the radiant heat given of by the heating elements 46 and 48 strike the reflectors 50 and 52 and are rellected outwardly thereby through the apertures 54 and 56.

The housing is divided into three successively adjacent chambers 74, 76 and 78 by a pair of transverse baille plates 80 and 82 which are secured to the rear wall portions 12 and 13 and the front wall portions 20 and 22 of the housing by any desired 0r conventional means. These baille plates 80 and 82 are spaced inwardly from the end walls 14 and 16 beyond the ends of the reflectors 50 and 52, and are positioned so that the central chamber 76 is slightly larger than either of the two end chambers 74 and 78. The ballles are preferably symmetrically arranged within the housing 10 so that the end chambers 74 and 78 are of approximately equal size. The end chambers 74 and 78 function as air inlet chambers and the central chamber 76 as an air outlet chamber, as hereinafter described in greater detail.

The baille plates 80 and 82 are circularly notched at their central rear portions to define in conjunction with the rear wall of the housing 10 substantially circular apertures 84 and 86 within which fans 88 and 90, respectively, are mounted. These fans 88 and 90 are mounted upon the single, double-ended shaft 92 of an electric motor 94 which is iixedly supported within the central chamber 76. Preferably, the motor 94 is mounted upon resilient supports such as the rubber mounting blocks 96 illustrated to minimize transmission of vibration and noise to the housing 10 during operation. Brackets 98 are spot welded or otherwise secured to the rear wall of the housing 10 to support the motor 94 in axial alignment with the apertures 84 and 86.

' The fans 88 and 90 are radially aligned with the baille plates 80 and 82, respectively, and are of opposite pitch so that when they are rotated in the same angular direction, they draw air inwardly from the inlet chambers 74 and 78 into the outlet chamber 76.

Inlet apertures 100 and 102 are provided in the upper and lower front wall portions 20 and 22, respectively," to admit air into the inlet chambers '74 and 78. Thei apertures 100 in the upper front wall portion 20 may be in the form of notches cut in the upper corners of the upper front wall portion 20, extending approximately from the end walls 14 to the baille plates 80 and 82. They are disposed entirely above the upper reilector 50. The inlet apertures 102 in the lower front wall portion 22`are arranged symmetrically with respect to the upper inlet apertures 100, being located in the lower corners of the front wall below the lower reflector 52. Outlet apertures 104 and 106 are formed in the upper and lower front wall portions 20 and 22, respectively, the outlet vapertures 104 and 106 communicating with the outlet chamber 76. The outlet apertures 104 and 106 extend 4substantially the full width of the outlet chamber 76 and are disposed entirely above and entirely below the upper and lower reilectors and 52, respectively. In practice, the inlet and outlet apertures 100 and 102, and 104 and 106 may be formed by notching the outer edges of the upper and lower front wall portions 20 and 22 along substantially their entire lengths, in which case the in- 4 lets are separated from the outlets by the bae plates and 82.

In the operation of the heater, the fans 88 and 90 draw air inwardly from the ambient atmosphere through the inlet apertures and 102 and into the inlet charnbers 74 and 78, the incoming air being initially heated as it passes over the portions of the reilectors 50 and 52 which extend into the inlet chambers, as well as by the surfaces of the housing and baffle plates. The air is then forced into the outlet chamber 76 by the fans, the air from the two inlet chambers being intimately mixed in the outlet chamber. The air forced into the outlet chamber 76 by the fans 88 and 90 is also heated within the chamber 76 by radiation from and contact with the reflectors 50 and 52, the walls of the housing 10 and the baille plates 80 and 82, and the air is expelled from the outlet chamber 76 at a relatively high velocity through the outlet apertures 104 and 106, the air being directed'for- `wardly in the general direction in which the heater faces.

Means are also provided for heating the air as it is expelled from the outlet apertures 104 and 106 by mixing with such air additional `air that has been directly heated within the reflectors 50 and 52 by the heating elements 46 and 48. For this purpose, the upper forward edge 62 of the upper reilector 50 is centrally notched to provide a relatively narrow slot 107 extending along substantially the entire width of the outlet chamber 76 and affording communication between the interior of the reilector S0 and the outlet chamber 7 6. When the heating element 46 is energized, it heats the air surrounding it within the reilector 50 producing an upwardly flowing convection current, with the result that air tends to ow inwardly into the rellector 50 through the lower portion of the front wall aperture 54 and outwardly through the slot 107 into the outlet chamber 76.

During operation of the heater, the aspirator eilect of the air owing from the outlet chamber 76 through the outlet aperture 104 reinforces the normal, heat-generated convection current, with the result that the air ilowing from the outlet chamber 76 and passing outwardly across the reflector slot 107 draws air upwardly through the slot 107 and carries it along in the stream emitted from the aperture 104. This additional air drawn through the slot 107 has been heated within the reflector 50 by contact with the reflector and the heating element 46 and by radiation. The effect is not only to increase the temperature of the outlet air stream, but also to cool the heating element 46 and thereby to reduce the heat radiated ouwardly therefrom to a more comfortable level than it would otherwise achieve.

The arrangement in the lower portion of the heater for effecting additional heating of the air expelled through the lower outlet aperture 106 is different from the arrangement just described in the upper portion since the lower outlet aperture 106 lies below the lower reflector 52, and it is desired to draw air downwardly from the reflector 52 in a direction opposite from the normally generated convection ilow. In the lower rellector 52 the convection effect opposes the aspirator etect of the air ilowing through outlet 106.

ln order to compensate for this dillerence occasioned by the direction of convection ow, the lower reflector 52, besides being notched to provide a slot 108 along its lower edge symmetrically with respect to the slot 107, also is notched along its upper edge to provide a slot 110 extending along :substantially the entire width of the outlet chamber 76. This slot 110 provides communication between the vertically central portion of the outlet chamber 76 and the interior of the lower reflector 52. In the operation of the heater, pressurized air in the central portion of the outlet chamber 76 flows downwardly through the slot 110 into the lower reilector 52 to countenact the development of a convection current ow, and to drive air heated within the reflector S2 downwardly toward the lower slot 108. The 'air heated within the reflector v52 is then aspirated downwardly through the slot 108 by thevstream of air flowing through the outlet aperture 106, with the result that a desirable balance in temperature between the upper and lower exhaust streams is achieved.

The arfiiows through the outlet apertures 104 and 106 ata relatively high velocity `so that it will carry forwardly of the device a substantial distance to heat a relatively large volume of space immediately in front of the heater.

The heater elements 46 and 48 and the motor 94 may be arranged in any desired operative electrical circuit. A typical circuit for satisfactory operation is illustrated in Fig. 5. .In this circuit, the heater elements 46 and 48 are connected in series with each other and in parallel with the motor 94. Control of the energization of the motor 94 Iand the heater elements 46 and 48 is effected through a conventional safety cut-off switch 112, and a conventional thermostatically controlled On-Off switch 116, all of which are connected in Iseries, and the opening of any one of which serves to de-energize both the motor 94 and the heater elements 46 and 48. The thermostatically controlled On-Off switch 116 may conveniently be mounted as shown on the face of the heater for easy access, and is preferably mounted within the housing in one of the inlet chambers 74 and 78. The safety switch 112 illustrated is spring biased towards its open position and is mounted near the front of the heater. The `safety switch 112 includes a downwardly `extending arm 118 which is disposed adjacent one of the forward legs 24 of the heater and arranged to be moved upwardly to close the switch 112 when the heater is resting in its normal position upon 'a surface. If the heater is raised from the surface, or if it is tipped or knocked over, the arm 118 is released and is moved downwardly by the spring 120 to open the switch 112 to de-energize both the motor 94 and the heating elements 46 and 48.

While 'a preferred embodiment of the invention has been shown and described, it will be understood that various changes and modifications may be made without departing from the spirit of the invention.

What is claimed is:

1. A space heater comprising, in combination, 'a houslng defining a main chamber #and having an inlet aperture and an outlet aperture communicating with said main chamber, a reflector member mounted within said housing and defining a reflector chamber, a heating element mounted within said reflector member and effective to heat air therein, Isaid reflector member being disposed above said outlet aperture and defining a first reflector aperture adjacent to said outlet aperture and affording communication between said main chamber and said reflector chamber, said reflector member also defining a second reflector aperture positioned remotely from said outlet aperture and affording communication between said main chamber and said reflector member, means for lpressurizing air within said main chamber, and means for directing the flow of such pressurized air so that a portion of such air flows outwardly across said first reflector aperture and through said outlet aperture thereby aspirating air through said first reflector aperture while another portion of such pressurized air flows into said reflector chamber through said second reflector aperture and then through said first reflector aperture to mix with the air flowing outwardly through said outlet aperture.

2. A space heater comprising, in combination, a-housing defining a main chamber having an inlet aperture and spaced upper and lower outlet apertures, an upper reflector member mounted within said housing and defining an upper reflector chamber therein, a lower reflector member mounted within said housing and defining a lower reflector chamber therein, heating elements disposed within said reflector chambers `and effective to heat air therein, said upper reflector member being disposed below said upper outlet aperture and defining an upper aspirator aperture adjacent thereto affording communication between said main chamber and said upper reflector chamber, said lower reflector member being disposed above said lower outlet aperture and defining a lower aspirator aperture adjacent thereto affording communication between said main chamber and said lower reflector chamber, said lower reflector also defining a second aperture remote from said lower aspirator aperture and affording communication between said main chamber and said lower reflector member, and means for forcing air from within said main chamber outwardly through said upper and lower outlet apertures thereby to a'spirate air from said upper reflector chamber through said upper laspirator aperture and from said lower reflector chamber through the lower aspirator aperture, said second reflector aperture being disposed so that a portion of the air in said main chamber flows from said main chamber through said second reflector 'aperture into said lower reflector chamber to counterbalance the tendency toward convection current generation in said lower reflector chamber during operation of said heater.

3. An electrical space heater comprising, in combination, 'a housing defining a main chamber, Ia pair of baffle plates extending transversely `across said main chamber within said housing and dividing said main chamber into a central outlet chamber and spaced inlet chambers, upper :and lower reflectors mounted within said housing and defining upper and lower reflector chambers therein, electrical heating elements disposed with said reflector chambers, each of said baille plates defining an aperture affording communication between said outlet chamber and one of said inlet chambers, and fan means effective to force air from said inlet chambers into said outlet chamber, said housing also defining inlet :apertures affording communication between said inlet cham'bers and the ambient atmosphere and outlet apertures affording communication between said outlet chamber and the ambient atmosphere.

4. An electrical space heater comprising, in combination, a horizontally disposed housing defining a main chamber, a pair of baffle plates extending transversely across said main chamber within said housing and dividing said main chamber into a central outlet chamber and spaced inlet chambers, said housing also defining inlet apertures affording communication between said inlet chambers and the ambient atmosphere and outlet apertures affording communication between said outlet chamher and the ambient atmosphere, upper and lower reflectors mounted within said housing and defining upper and lower reflector chambers therein, electrical heating elements disposed within said reflector chambers, each of said baille plates defining an aperture affording communication between said outlet chamber and one of said inlet chambers, fan means effective to force air from said inlet chambers into said outlet chamber, and means operative to draw air from said reflector chambers into said outlet chamber when air flows from said outlet chamber through said outlet apertures.

5. An electrical space heater comprising, in combination, a housing defining a main chamber, a pair of bafile plates extending transversely across said main chamber within said housing and dividing said main chamber into a central outlet chamber and a pair of inlet chambers, upper and lower reflectors mounted within said housing and defining upper and lower reflector chambers therein, electrical heating elements disposed within said reflector chambers, each of said baflle plates defining an aperture affording communication between said outlet chamber and one of said inlet chambers, fan means effective to force air from said inlet chambers into said outlet chamber, said housing defining inlet apertures affording communication between said inlet chambers and the ambient atmosphere, said housing also defining outlet apertures affording communication between said outlet chamber and the ambient atmosphere, and means operative only when air driven by said fan means flows from said outlet chamber through said outlet .apertures for drawing air from said reflector chambers.

6. An electrical space heater comprising a horizontally disposed housing defining a main chamber, a pair of bafe plates extending transversely across said main chamber within said housing and dividingsaid main chamber into a central outlet chamber and a pair of spaced inlet chambers, upper and lower refiectors mounted within said housing and extending into said inlet and outlet charnbers, said reflectors defining upper and lower reector chambers therein, electrical heating elements disposed within said reflector chambers, each of said baffie plates defining an aperture affording communication between said'outlet chamber and one of said inlet chambers, a pair of fans mounted within said :apertures defined by said baffle plates, means to drive said fans rotationally in the same angular direction, said fans being of opposite pitch so that when they are driven in said direction they force air from said inlet chambers into said outlet chamber, said housing defining inlet apertures affording communication between said inlet chambers and the ambient atmosphere, said housing also defining outlet apertures affording communication between said outlet chamber and the ambient atmosphere.

7. An electrical space heater comprising a horizontally disposed housing defining a main chamber, a pair of baffle plates extending transversely across said main chamber within said housing and dividing said main chamber into a central outlet chamber and a pair of spaced inlet chambers, upper and lower reflectors mounted within said housing and extending into each of said inlet and outlet chambers, said upper and lower reflectors defining upper and lower refiector chambers therein, electrical heating elements -disposed within said refiector chambers, each one of said bafiie plates dening in conjunction with said housing an aperture affording communication between said outlet chamber and a respective one of said -inlet chambers, a pair of fans mounted within the apertures defined by said bafe plates, means to drive said fans rotationally in the same angular direction, said fans being of opposite pitch so that when they are driven in said direction they force air from said inlet chambers into said outlet chamber, said housing also defining inlet apertures affording communication between said inlet chambers and the ambient atmosphere and outlet apertures affording communication between said outlet chamber and the ambient atmosphere.

8. In combination with a space heater having a housing with a sloping rear wall portion, a combination adjustable leg and handle member comprising an elongated leg portion substantially conforming to the cross-sectional shape of said rear wall portion and extending downwardly therefrom to support said rear wall portion above a surface, and clamping means to adjustably secure said member to said wall portion.

9. In combination with a space heater having a housing with a sloping rear wall portion, a combination adjustable leg and handle member comprising an elongated leg portion substantially conforming fto the cross-sectional shape of said rear wall portion and extending downwardly therefrom to support said lrear Wall portion above a surface, clamping means to adjustably secure said member to said wall portion, the upper end of said member being bent outwardly to form a handle.

10. In combination with a space heater having a housing with a sloping rear wall portion, a combination ad justable leg and handle member comprising an elongated leg portion substantially conforming tothe cross-sectional shape of said rear wall portion and extending downwardly therefrom to support said rear wall portion above a surface, clamping means to adjustably secure said member to said wall portion, and alignment means to maintain said member in predetermined alignment with respect to said wall portion when said member is clamped to said wall portion by said clamping means, the upper end of said member being bent outwardly to form a handle.

1l. A space heater comprising, in combination, a housing defining a vertically oriented face and a curved upper rear wall portion, a pair of spaced legs extending downwardly from said housing adjacent to the face thereof, and a combination leg and handle member adjustably secured to said upper rear wall portion, said member including an elongated curved leg portion, a substantial portion of which is shaped to conform to the curvature of said upper rear wall portion, said member also extending upwardly from the point at whichI it is secured to` said wall portion and being bent rearwardly at its upper end to form a handle, and means for releasably securing said member to said housing.

12. A space heater comprising, in combination, a housing having a curved upper rear wall portion, a combination leg and handle member adjustably secured to said wall portion, said member including a curved leg portion shaped to conform to the curvature of said wall portion, the upper end of said member being bent outwardly to form a handle, a channel fixed to said wall portion, the legs of said channel extending outwardly from said wall portion and defining a guideway to receive said leg portion and hold said member in alignment with respect to said housing, and means for releasably securing said member to said housing.

References Cited in the file of this patent UNITED STATES PATENTS 1,749,039 Lincecum Mar. 4, 1930 1,908,559 Roser May 9, 1933 2,081,565 Wahl May 25, 1937 2,167,122 Metcalf July 25, 1939 2,385,295 MacGregor Sept. 18, 1945 2,614,201 Varis Oct. 14, 1952 

